Releasable tether retention system

ABSTRACT

The present invention incorporates a tether release system within a conventional airbag system or a conventional vehicle occupant protection system. Release of an associated tether may simultaneously open a vent on an associated airbag. A housing contains an actuator contained within the housing for actuation of the tether release system upon receipt of a crash detection signal, for example. A first moving member is configured for receipt of a propulsive force emanating from the actuator upon actuation of the tether release system. A movable tether release member is contained within the housing wherein the movable tether release member operably communicates with the first moving member upon actuation of the tether release system, for release of an associated tether.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Application Ser. Nos.61,351,237, 61,357,808, and 61/351,615, having filing dates of Jun. 3,2010, Jun. 23, 2010, and Jun. 4, 2010, respectively.

BACKGROUND OF THE INVENTION

Airbags and other pliable and inflatable restraints are being designedusing releasable tethers to selectively modify the shape of therestraint, to provide the restraint with enhanced rigidity, and tocontrol venting of the restraint during deployment. In certainembodiments, tension in the tether maintains a valve controlling anairbag vent in a closed position. At some point during or afterdeployment of the inflatable device, tension in the tether may berelieved to permit actuation of the vent valve and subsequent release ofairbag gases.

The embodiments of the present invention provide a releasable tetherretention system and if desired, an airbag vent valve actuationmechanism designed to retain at least one end of an extensible tetherand to release the tether upon application of an activation signal to anactuator.

SUMMARY OF THE PRESENT INVENTION

The present invention incorporates a tether release system within aconventional airbag system or a conventional vehicle occupant protectionsystem. Release of an associated tether may simultaneously open a venton an associated airbag designed to deflate or depressurize the airbagonce actuated. As described below, the tether is operably supported bythe tether release system, prior to actuation of the system.

A housing having a first end and a second end is secured to a base,wherein the base may be integrated within a vehicle component such as adash board structure, for example. A pyrotechnic, pneumatic, hydraulic,or other functionable actuator is fixed or sealed within the first endof the housing for actuation of the tether release system upon receiptof an electronic or mechanical crash detection signal, from a vehiclealgorithm, for example. A first moving member such as a piston orplunger, for example, may be juxtaposed to the actuator within thehousing, for receipt of a propulsive force emanating from the actuatorupon actuation of the tether release system. A second moving member or amovable tether release member is contained within the housing andjuxtaposed to the second end of the housing; the movable tether releasemember operably communicates and/or cooperates with the first movingmember upon actuation of the tether release system, thereby releasingthe tether supported by and/or associated with the movable tetherrelease member prior to actuation thereof.

Stated another way, the present invention may be described as areleasable tether retention system including a housing; a retentionmechanism operably coupled to the housing; and an element movablymounted within the housing and operatively coupled to the retentionmechanism such that the retention mechanism is actuatable by movement ofthe member from a first position to a second position. It will beappreciated that the retention mechanism is configured to secure atether thereto when the element is in the first position, and is furtherconfigured to release the tether upon movement of the element from thefirst position to the second position.

It will be appreciated that the aforementioned tether may be released ina variety of methods in accordance with the inventive principles of thepresent invention, and as exemplified by, but not limited by, theillustrative embodiments described below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-6C show various views of a releasable tether retention systemand associated components thereof in accordance with one embodiment ofthe present invention.

FIGS. 7-11 show various views of a releasable tether retention systemand associated components thereof in accordance with a second embodimentof the present invention.

FIGS. 12-16 show various views of a releasable tether retention systemand associated components thereof in accordance with a second embodimentof the present invention.

FIG. 17 is a schematic representation of an exemplary vehicle occupantprotection system incorporating a releasable tether retention system inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1A-6C, a releasable tether retention system 10 inaccordance with one embodiment of the present invention includes ahousing 12, a support element 14, a first movable member 15 slidablymounted in housing 12, a second movable member or sliding element 16coupled to the first movable member 15, and an actuator 18 operativelycoupled to housing 12 for producing a motion of first movable member orpiston 15 after receipt of an actuation signal.

Housing 12 has a first end 30 with a first opening 30 a and a second end32 opposite first end 30. The second end 32 includes a second opening 32a. In the embodiment shown, openings 30 a and 32 a are substantiallycoaxial along an axis A of the housing. An axial bore 24 extends throughhousing 12 between first end 30 and second end 32. In a particularembodiment, first end 30 of the housing 12 is configured so as to becrimpable or otherwise deformable to aid in retaining actuator 18 within(or to) housing 12. Housing 12 may include features such as shoulder 12a configured to limit the travel of movable member 15 (described below)within bore 24 during operation of the tether retention system. Housing12 may be formed using any suitable method from a metallic material orany other suitable material.

A base 20 is provided for mounting of housing 12 thereto. In oneembodiment, base 20 comprises an integral portion of a vehicle or otherdevice to which tether retention system 10 is to be attached. In anotherembodiment, base 20 is formed separately from the vehicle or otherelement and is attached by welding or any other suitable method to aportion of the vehicle or other device to which the tether retentionsystem is to be secured. Base 20 includes an opening 20 b formed thereinto permit tether 22 to extend therethrough. Housing 12 is mounted to thebase 20 proximate opening 20 b. In an alternative embodiment, housing 12is secured to another portion of the vehicle or device to which thetether retention system is mounted, but is still positioned and securedproximate opening 20 b.

A support element 14 is provided for engaging and supporting a portionof a tether 22 prior to release of the tether. Support element 14 ispositioned and secured spaced apart from base 20 and the opening 20 bformed therein. In the embodiment shown in the drawings, opening 20 b ispunched or otherwise formed in base 20, and a portion of the basematerial that occupied opening 20 b is formed or otherwise shaped toprovide support element 14. In this embodiment, support element 14 isspaced apart from both base 20 and its opening 20 b by forming part ofthe material of support element 14 into a connecting section 14 a whichjoins support element 14 to the remainder of base 20.

In alternative embodiments, support element 14 may be formed separatelyfrom base 20 and suitably attached to the base, or the support elementmay be positioned spaced apart from the base 20 and opening 20 b andcoupled to an element separate from the base. In a particularembodiment, base 20 and/or support element 14 incorporate a feature orfeatures (not shown) configured to limit the travel of second movablemember or sliding element 16 (described below) or first movable memberor element 15 (described below). Base 20 may be formed using anysuitable method from a metallic material or any other suitable material.Support element 14 may be formed using any suitable method from ametallic material or any other suitable material. As described below,taken together, support element 14 and second movable member or slidingelement 16 constitute a releasable tether retention mechanism 14/16 thatthat when coupled to the housing 12 and first movable member 15,facilitates the retention and subsequent release of an associated tetherupon actuation of the system 10.

An actuator 18 is secured to housing first end 30 and extends into bore24 so as to enable fluid communication between the actuator and bore 24containing first movable member 15, after activation of the system torelease the tether. In one embodiment, actuator 18 is in the form of anelectrically-actuated pyrotechnic initiator, or squib, secured within abore seal 36. Actuator 18 may be formed as known in the art. Oneexemplary actuator construction is described in U.S. Pat. No. 6,009,809,herein incorporated by reference. Bore seal 36 may be stamped, extruded,cast, machined, or otherwise metal formed and may be made from carbonsteel or stainless steel, for example.

Actuator 18 may be secured within bore seal using any of a variety ofknown methods including, but not limited to, an interference fit,adhesive application, or crimping. Similarly, bore seal 36 may besecured to housing 12 using any of a variety of known methods including,but not limited to, crimping, welding, or adhesive application. Inaddition, features may be provided for engaging the actuator and/or boreseal with base 20 or a portion of the vehicle or device to which system10 is mounted, to aid in preventing rotation or other movement of theactuator relative to housing 12 and/or base 20.

In alternative embodiments, actuator 18 may be in the form of apneumatically or hydraulically actuated valve coupled to an end ofhousing 12 so as to enable fluid communication between an outlet of thevalve and bore 24 upon receipt by the retention system of a suitableactivation signal. In these embodiments, activation of the system torelease the tether results in opening of the valve to admit ahigh-pressure fluid into bore 24, resulting in movement of the firstmovable member 15 as described below. Alternatively, actuator 18 may bepositioned remotely from housing 12 but so as to enable fluidcommunication between the actuator and bore 24 upon receipt by theretention system of a suitable activation signal.

First movable member 15 is configured to slidably move along and withinbore 24. In one embodiment, a detent feature (not shown) is provided forensuring sufficient engagement or interference between the movablemember and housing 12 such that movement of the first movable member 15within bore 24 is prevented prior to activation of the system to releasethe tether. In the embodiment shown in the drawings, movable memberportion 15 a has a groove 15 b formed therein for engaging a portion ofthe second movable member or sliding element 16.

In one particular embodiment, the detent feature is in the formed of aknurl, stake, or other deformation (not shown) in a surface of themovable member which engages a wall of the housing defining the bore 24.

In another particular embodiment, the detent feature is formed in thehousing, rather than in the movable member 15.

In another particular embodiment, the detent effect is provided bydimensioning the bore diameter and an outer diameter or dimension of themovable member 15 such that a slight interference between the movablemember and the housing is provided when the movable member is in apre-activation position.

In another particular embodiment, the movable member 15 and/or thehousing 12 include one or more features configured to produce a slowingof movable member 15 as it approaches housing second end 32 afteractivation of the system to release the tether. This slowing effect maybe provided by dimensioning the bore diameter and an outer diameter ordimension of the movable member 15 such that an interference fit betweenthe movable member and the housing is provided as the movable memberapproaches housing second end 32. In one example, a diameter of the bore24 is tapered from a relatively larger dimension to a relatively smallerdimension along the direction of movement of movable member 15, so thatslowing of the movable member is relatively gradual. The rate ofdeceleration of the movable member along bore 24 may be controlled tosome degree by the severity of the taper. A portion 15 a of movablemember 15 extends out of housing 12 to enable coupling of slidingelement 16 thereto.

The dimensions of the movable member may also be specified so as toaffect the rate of deceleration of the movable member within the housing12.

First movable member/piston 15 may be formed from a metallic material orany other suitable material.

Second movable member/sliding element 16 has a first portion 16 a and asecond portion 16 b extending from first portion 16 a. Portion 16 a hasan opening 16 c formed therein to permit a portion of tether 22 toextend therethrough. Prior to activation of the system 10 to release thetether, first portion 16 a is positioned between base 20 and supportelement 14 such that opening 16 c resides between base opening 20 b andthe support element.

In the embodiment shown in the drawings, second portion 16 b has a slot16 d for receiving therein a grooved portion 15 a of movable member 15.In this manner, the sliding element 16 is engaged with the movablemember 15 so that the sliding element moves in conjunction with themovable member. In one particular embodiment, slot 16 d is open-ended topermit the movable member grooved portion 15 a to be inserted into theopen end.

In another particular embodiment (shown in FIG. 3), the slot has akeyhole-shape, with first section 16 d 1 configured to permit insertionof an end 15 e of the movable member therein, and a second section 16 d2 adjoining the first section, for engaging movable member groovedportion 15 a. Slot second section is sized to receive movable membergrooved portion 15 a therein, but also to prevent withdrawal of end 15 atherethrough. Thus, end 15 a is inserted into first section 16 d 1 untilgrooved portion 15 a is aligned with second section 16 d 2. Then groovedportion 15 a is inserted into second portion 16 d 2 to couple thesliding element 16 to movable member 15.

Sliding element or second movable element 16 may be formed from ametallic material or any other suitable material.

As shown in FIG. 1, prior to activation of the system to release tether22, a looped end 22 a of the tether passes through base opening 20 b andthrough sliding element opening 16 c and is looped over support element14. Sliding element second portion 16 b and an edge 16 a 1 of firstportion 16 a bracket the tether, preventing motion of the tetherparallel to axis A and preventing the tether end 22 a from sliding offof support element 14. This configuration also ensures that the tetherend 22 a will move in conjunction with sliding element 16. Referring toFIG. 1D, sliding element opening 16 c may also be configured such thatforces acting on tether 22 in the direction indicated by arrow “B” inFIG. 1A are transmitted to parts 16 e, 16 f of first portion 16 a oneither side of opening 16 c, via the portions of the tether squeezedbetween the support element 14 and parts 16 e, 16 f. In this manner,parts 16 e, 16 f act to reinforce support element 14 against tensionforces acting on the tether, to aid in preventing bending of the supportelement.

A securement member 50 (for example, a conventional hold-down strap) maybe used to secure the housing 12 to base 20 or to another portion of thevehicle or device to which the system 10 is attached. However, housing12 may be secured to base 20 by welding or by any other suitable method.

Referring to FIGS. 5A-5F, system 10 may be assembled as follows. Slidingelement 16 is positioned in its pre-activation position in relation tobase 20. Tether end 22 a is then slid through base opening 20 b andsliding element opening 16 c. Tether portion 22 a is then slid oversupport element 14 and sliding element 16 is slid between the supportelement and base 20 such that the support element extends into the loopof tether end 22 a. Housing 12 with movable member 15 residing thereinis then positioned such that the exposed end of the first movable member15 engages the second movable element or sliding element 16 aspreviously described. Housing 12 is then secured to base 20 usingsecurement member 50.

Referring to FIGS. 1A-6C, in operation, upon receipt of a signal from acrash sensor or other system activation mechanism, an activation signalis sent to actuator 18. In an embodiment where the actuator is a squib,combustion products from the squib impinge on an end face of movablemember 15 in fluid communication with the actuator, forcing the movablemember in the direction indicated by arrow “C” in FIG. 2. Slidingelement or second movable member 16 moves in conjunction with firstmovable member 15, forcing the tether looped end 22 a (which is trappedbetween sliding element edge 16 a 1 and second portion 16 b) to move indirection “C”. This motion forces the lopped end 22 a to slide off ofthe free end of support element 14. When looped end 22 a is disengagedfrom support element 14, the looped end is free to pass through opening16 c in sliding element 16 and through base opening 20 b, therebyfreeing the tether.

FIG. 17 shows a particular application of a releasable tether retentionsystem 10 in accordance with the present invention. Referring to FIG.17, the releasable tether retention system 10 is incorporated into avehicle occupant protection system 180 including additional elementssuch as, for example, a safety belt assembly 150 and/or an airbagmodule. FIG. 17 shows a schematic diagram of one exemplary embodiment ofsuch a protection system. Tether retention system 10 may be in operablecommunication with a crash event sensor 210 which is in communicationwith a known crash sensor algorithm that signals actuation of the tetherrelease mechanism via activation of actuator 18 based on any desiredcriteria, for example, the occurrence of a collision event, deploymentof a vehicle airbag, the occurrence of a predetermined occupantcondition, or any other desired criteria.

Safety belt assembly 150 includes a safety belt housing 152 and a safetybelt 225 in accordance with the present invention extending from housing152. A safety belt retractor mechanism 154 (for example, a spring-loadedmechanism) may be coupled to an end portion of the belt. In addition, asafety belt pretensioner 156 may be coupled to belt retractor mechanism154 to actuate the retractor mechanism in the event of a collision.Typical seat belt retractor mechanisms which may be used in conjunctionwith the safety belt embodiments of the present invention are describedin U.S. Pat. Nos. 5,743,480, 5,553,803, 5,667,161, 5,451,008, 4,558,832and 4,597,546, incorporated herein by reference. Illustrative examplesof typical pretensioners in system 150 are described in U.S. Pat. Nos.6,505,790 and 6,419,177, incorporated herein by reference.

Safety belt system 150 may be in communication with a crash event sensor158 (for example, an inertia sensor or an accelerometer) including aknown crash sensor algorithm that signals actuation of belt pretensioner156 via, for example, activation of a pyrotechnic igniter (not shown)incorporated into the pretensioner. U.S. Pat. Nos. 6,505,790 and6,419,177, incorporated herein by reference, provide illustrativeexamples of pretensioners actuated in such a manner.

If desired, one or more of sensors 210 and/or 158 may be operativelycoupled to valve release mechanism actuator 18 to provide one or moreassociated inputs prompting activation of the valve release mechanism,depending on such factors as vehicle occupant weight, elapsed time sincethe occurrence of a collision event, or any other pertinent factors.

In yet other embodiments illustrating the present invention, andreferring to FIGS. 7-11, an airbag vent valve actuation mechanism ortether release system 310 in accordance with one embodiment of thepresent invention includes a housing 312, a first movable member orelement 315 slidably mounted in housing 312, an actuator 318 operativelycoupled to housing 312 for producing a motion of movable member 315after receipt of an actuation signal, a link 316 coupled to the firstmovable member 315, and a second movable member or rotatable element 319coupled to the link 316 for supporting a tether 322 prior to activationof the valve actuation mechanism. As described below, taken together,the link 316 and second movable member or rotatable element 319 whencoupled to the housing 312 and the first movable member or element 315constitute a releasable tether retention mechanism 316/319 thatfacilitates the retention and subsequent release of an associated tetherupon actuation of the system 310.

Housing 312 has a first end 330 with a first opening 330 a and a secondend 332 opposite first end 330. The second end 332 includes a secondopening 332 a. In the embodiment shown, openings 330 a and 332 a aresubstantially coaxial along an axis A of the housing. An axial bore 324extends through housing 312 between first end 330 and second end 332. Ina particular embodiment, first end 330 of the housing 312 is configuredso as to be crimpable or otherwise deformable to aid in retainingactuator 318 within (or to) housing 312. Housing 312 may includefeatures such a shoulder (not shown) configured to limit the travel ofmovable member 315 (described below) within bore 324 during operation ofthe airbag vent valve actuation mechanism.

In another particular embodiment (shown in FIGS. 7-11), a portion of anactuator 318 (described below) extends into and is secured withinhousing first end 330, and a portion of the actuator extends outside ofthe housing first end. Housing first end 330 is then secured within abore seal 336 so as to enclose the portion of the actuator extendingfrom housing end 330. Bore seal may then provide an interface permittingmating of a connector or other suitable signal transmission medium (notshown) with the actuator 318.

Housing 312 may be mounted to any suitable surface, for example, to aportion of a vehicle or device to which the valve actuation mechanism isoperatively coupled. In a particular embodiment, the housing is mountedto a base 320 (described below) to which rotatable element 319(described below) is also mounted. In another embodiment, the mountingsurface for housing 312 is formed separately from the vehicle or deviceand is attached by welding or any other suitable method to a portion ofthe vehicle or device. Housing 312 is mounted to its mounting surface soas to remain fixed or stationary with respect to base 320. Housing 312may be formed using any suitable method from a metallic material or anyother suitable material.

First movable member or piston 315 is configured to slidably move alongand within bore 324. First movable member 315 is positioned either influid communication with actuator 318 (described below) or so as toenable fluid communication with the actuator after activation of thevalve actuation mechanism. Activation of first movable member 315 in themanner described below produces motion of the movable member within bore324.

In one embodiment, a detent feature (not shown) is provided forpreventing movement of the first movable member 315 within bore 324prior to activation of the valve actuation mechanism. In one particularembodiment, the detent feature is in the form of a knurl, stake, orother deformation (not shown) in a surface of the movable member whichengages a wall of the housing defining the bore 324. In anotherparticular embodiment, the detent feature is formed in the housing,rather than in the first movable member 315.

First movable member 315 may be formed from a metallic material or anyother suitable material.

An actuator 318 is secured in housing first end 330 and extends intobore 324 so as to enable fluid communication between the actuator andbore 324 containing piston or first movable member 315, after activationof the valve actuation mechanism. In one embodiment, actuator 318 is inthe form of an electrically-actuated pyrotechnic initiator, or squib,secured within bore seal 336 or housing 312. Actuator 318 may be formedas known in the art. One exemplary actuator construction is described inU.S. Pat. No. 6,009,809, herein incorporated by reference. Bore seal 36may be stamped, extruded, cast, machined, or otherwise metal formed andmay be made from carbon steel or stainless steel, for example.

Actuator 318 may be secured within bore seal using any of a variety ofknown methods including, but not limited to, an interference fit,adhesive application, or crimping. Similarly, bore seal 336 may besecured to housing 312 using any of a variety of known methodsincluding, but not limited to, crimping, welding, or adhesiveapplication. In addition, features may be provided for engaging theactuator and/or bore seal with base 320 or a portion of the vehicle ordevice to which system 310 is mounted, to aid in preventing rotation orother movement of the actuator relative to housing 312 and/or base 320.

In alternative embodiments, actuator 318 may be in the form of apneumatically or hydraulically actuated valve coupled to an end ofhousing 312 so as to enable fluid communication between an outlet of thevalve and bore 324 upon receipt by the retention system of a suitableactivation signal. In these embodiments, activation of the system toactuation the tether results in opening of the valve to admit ahigh-pressure fluid into bore 324, resulting in movement of the movablemember 315 as described below. Alternatively, actuator 318 may bepositioned remotely from housing 312 but so as to enable fluidcommunication between the actuator and bore 324 upon receipt of asuitable activation signal by the valve actuation mechanism.

A link 316 is coupled to movable member 315 so as to move in conjunctionwith the movable member. Link 316 is also coupled to a second movablemember or rotatable element 319 (using a bolt, rivet, or other suitablemechanism) so as to produce rotation of the rotatable element withrespect to the link responsive to motion of the link within housing 312after activation of the valve actuation mechanism. In the embodimentshown in FIGS. 7-11, a portion of the link 316 is positioned and securedwithin a complementary cavity formed in movable member 315. Link 316 maybe formed from a metallic material or any other suitable material.

Base 320 may be any suitable mounting surface, for example, to a portionof a vehicle or device to which the valve actuation mechanism isoperatively coupled. In a particular embodiment, the base 320 is thesame surface to which housing 312 is mounted. In another embodiment,base 320 is formed separately from the vehicle or other device and isattached by welding or any other suitable method to a portion of thevehicle or device to which the valve actuation mechanism is to besecured.

Base 320 includes an opening 320 b formed therein to permit tether 322to extend therethrough for engaging rotatable element third portion 319c (described below). In the embodiment shown in the drawings, the secondmovable member or rotatable element 319 (described below) is rotatablymounted to the base 320 proximate opening 320 b. Opening 320 b has afirst portion 320 c over which rotatable member third portion 319 cextends prior to system activation and a second portion 320 e adjacentfirst portion 320 c and configured for permitting deflection of thirdportion 319 c therein and sliding of tether end 322 a from third portion319 c.

One or more features may be provided for restricting rotation ofrotatable element 319. In the embodiment shown in FIGS. 7-11, opening320 b is punched or otherwise formed in base 320, and a portion of thebase material that occupied opening 320 b is formed or otherwise shapedto provide a hard stop 320 h for restricting the rotation of rotatableelement 319. However, the rotation-restricting feature may be located onrotatable member 319 and configured to engage a portion of base 320, orthe rotation-restricting feature may have any of a variety ofalternative forms.

Base 320 may be formed using any suitable method from a metallicmaterial or any other suitable material.

Rotatable element 319 is rotatably coupled to link 316, as previouslydescribed. Rotatable element 319 is also rotatably mounted to base 320at using a bolt, rivet, or other suitable rotatable coupling 319 r. Inthe embodiment shown in the drawings, rotatable element 319 has a firstportion 319 a rotatably coupled to base 320 at rotatable coupling 319 r.A second portion 319 b extends from first portion 319 a and is rotatablycoupled to link 316, and a third portion 319 c extends from firstportion 319 a to span base opening first portion 320 c for engaging andsupporting a portion of a tether 322 prior to release of the tether.Rotatable coupling 319 r may comprise a bolt, a rivet, or any othersuitable connection configured for rotatably securing the rotatablemember 319 to base 320. In an alternative embodiment, rotatable element319 is rotatably mounted to another portion of the vehicle or device towhich the valve actuation mechanism is mounted, but is still locatedproximate opening 320 b.

Third portion 319 c extends across opening first portion 320 c as shownin FIG. 8 such that an end of third portion 319 c rests slidably on, orresides slightly spaced apart from, base 320 prior to placement oftether 322 on third portion 319 c. This permits the base 320 to supportthird portion 319 c against forces exerted by the tether prior to systemactivation.

Rotatable element third portion 319 c may also have a cross-section thatis relatively weaker or less resistant to deformation due to forcesexerted on the third portion by the attached tether. This cross-sectionis configured and positioned for facilitating bending or deformation ofthe third portion responsive to forces exerted on the third portion bythe tether after activation of the valve actuation mechanism andsufficient rotation of rotatable element 319. In the embodiment shown inFIGS. 7-11, the relatively weaker cross-section is provided by a notch319 n (see FIG. 8) formed along a surface of third portion 319 c toreduce the cross-sectional area of the third portion in a location whereit desired to facilitate bending of the third portion.

Rotatable element 319 may be formed using any suitable method from ametallic material or any other suitable material.

A securement member 350 (for example, a conventional hold-down strap)may be used to secure the housing 312 to base 320 or to another portionof the vehicle or device to which the system 310 is attached.Alternatively, the housing 312 may be welded or otherwise suitablysecured to its mounting surface.

As shown in FIGS. 7, 8, and 9, prior to activation of the system torelease tether 322, a looped end 322 a of the tether passes through baseopening 320 b and is looped over rotatable element third portion 319 c.In addition, as stated previously, rotatable element third portion 319 crests slidably on, or resides slightly spaced apart from, base portion320. This permits base portion 320 to support third portion 319 cagainst forces exerted by the tether prior to system activation.Movement of tether end 322 a along third portion 319 c is constrained byrotatable member first portion 319 a and by an edge of base openingfirst portion 320 c.

Referring to FIGS. 10 and 11, in operation, upon receipt of a signalfrom a crash sensor or other system activation mechanism, an activationsignal is sent to actuator 318. In an embodiment where the actuator is asquib, combustion products from the squib impinge on an end face offirst movable member 315 in fluid communication with the actuator,forcing the first movable member 315 in the direction indicated by arrow“C” in FIG. 10. Movement of the movable member 315 in direction “C”causes the second movable and rotatable member 319 connected to thefirst movable member 315 to rotate in direction “E” shown in FIG. 10.When third portion 319 c has rotated to a position over opening secondportion 320 e, the third portion 319 c is no longer supported by thebase 320. The third portion 319 c is thus permitted to deflect intoopening second portion 320 e responsive to forces exerted by the tether,allowing tether end 322 a to slide off a free end of the third portionas shown in FIG. 11.

In one embodiment, the tether 322 is operatively coupled to a valve (notshown) controlling a flow of inflation gases from a vent of an airbag(also not shown). The mechanism is structured so that the valve remainsclosed while the tether end 322 a is engaged with rotatable member thirdportion as shown in FIGS. 7 and 8. Activation of any of the valveactuation mechanism embodiments described herein produces rotation ofthe rotatable member and release of tether end 322 a as just described.As tether end 322 a begins to slide off of rotatable member thirdportion 319 c, tension in the tether starts to relax, permitting thevalve to open and allowing release of inflation gases from the airbag.

Embodiments of the valve actuation mechanism disclosed herein may beactivated to permit release of gases from the airbag in situations wherea smaller or lighter vehicle occupant is present during a crashsituation. Release of a portion of the gases from the inflated airbagprovides a relatively softer, less rigid cushion for the lighter vehicleoccupant.

FIG. 17 shows a particular application of a valve actuation mechanism310 in accordance with the present invention. Referring to FIG. 17, thevalve actuation mechanism may be incorporated into a vehicle occupantprotection system 180 including additional elements such as, forexample, a safety belt assembly 150 and/or an airbag module. FIG. 17shows a schematic diagram of one exemplary embodiment of such aprotection system. valve actuation mechanism 310 may be in operablecommunication with a crash event sensor 210 which is in communicationwith a known crash sensor algorithm that signals actuation of the valveactuation mechanism via activation of actuator 18 based on any desiredcriteria, for example, the occurrence of a collision event, deploymentof a vehicle airbag, the occurrence of a predetermined occupantcondition, or any other desired criteria.

In yet another embodiment of the invention, FIGS. 12-16 show an airbagvent valve actuation mechanism or tether release system 497 inaccordance with the present invention

An actuator housing 412 has a first end 430 with a first opening 430 aand a second end 432 opposite first end 430. In one embodiment, thehousing 412 is generally cylindrical, although a housing having any of avariety of alternative cross-sectional shapes may be used. An axial bore424 extends through housing 412 between first end 430 and second end432. Bore 424 is configured for slidably receiving an actuator 418therein, as described below. A wall (or walls) of housing 412 includesopposed, elongated slots 412 v formed therein. Slots 412 v areconfigured for receiving therein a portion of a locking pin 405(described below) to enable the received portions of the pin to slidingwithin the slots 412 v or along edges of the slots. After activation ofthe valve actuation mechanism, one or more end portions 412 w of theslots 412 v may serve as hard stops, limiting travel of pin 405 in thedirection indicated by arrow A.

In a particular embodiment, first end 430 of the housing 412 isconfigured so as to be crimpable or otherwise deformable to aid inretaining actuator 418 within (or to) housing 412. In another particularembodiment, an end of the housing is shaped so as to receive theactuator therein or so as to facilitate retention of the actuatortherein.

Housing 412 may include features such a shoulder (not shown) configuredto limit the travel of a movable member 415 (described below) withinbore 424 during operation of the airbag vent valve actuation mechanism.Housing 412 may be mounted to any suitable surface, for example, to aportion of a vehicle or device to which the valve actuation mechanism isoperatively coupled. Housing 412 is mounted to its mounting surface soas to remain fixed or stationary with respect to the mounting surface.Housing 412 may be formed using any suitable method from a metallicmaterial or any other suitable material.

A base 411 may be provided for mounting of housing 412 and otherelements of the system 410 thereon. Base 411 may be formed by a portionof a vehicle or other device on which the mechanism 410 is mounted.Alternatively, base 411 may be in the form of a stand-alone bracket orother structure which may be welded or otherwise suitably attached to aportion of the vehicle or device. In one embodiment, base 411 isconfigured so as to provide a clearance between the base and locking pin405 (described below) when the locking pin is mounted in first movablemember 415. Base 411 may be formed using any suitable method from ametallic material or any other suitable material.

In the embodiment shown in FIGS. 12-16, housing 412 is secured to base411 using a clamp 499 coupled to base 411. However, the housing 412 maybe secured to the base 411 or to the vehicle or other device using anyother suitable method.

Clamp 499 may be secured to base 411 using welding, riveting, or anyother suitable method. Clamp 499 has a base portion 499 a and a pair ofopposed aims 499 b extending from the clamp base portion to form acavity therebetween. Arms 499 b are configured to facilitate gripping orengagement of actuator housing 412 when the housing is positionedbetween the arms 499 b, thereby securing the housing 412 within thecavity.

The housing may be clamped or secured between the arms 499 b by forcingend portions of arms toward each other after housing 412 is insertedinto the cavity between the arms, until a desired engagement force isachieved. Then the arms 499 b are secured in the engagement positionusing a bolt 402 or other suitable means.

Clamp 499 may be formed using any suitable method from a metallicmaterial or any other suitable material.

An actuator 418 is secured in housing first end 430 and extends intobore 424 so as to enable fluid communication between the actuator andbore 424 containing movable member 415, after activation of the valveactuation mechanism. In one embodiment, actuator 418 is in the form ofan electrically-actuated pyrotechnic initiator, or squib, secured withina bore seal (not shown) or housing 412. Actuator 418 may be formed asknown in the art. One exemplary actuator construction is described inU.S. Pat. No. 6,009,809, herein incorporated by reference.

In the embodiment shown in FIGS. 12-16, a portion of actuator 418extends into and is secured within housing first end 430, and a portionof the actuator extends outside of the housing first end to enablemating of a connector 403 or other suitable signal transmission mediumwith the actuator 418.

The actuator 418 may be secured within a bore seal (not shown) mountablewithin housing 412 so as to provide a substantially gas-tight sealbetween the housing 412 and the bore seal, and also between the boreseal and the actuator 418. Actuator 418 may be secured within the boreseal using any of a variety of known methods including, but not limitedto, an interference fit, adhesive application, or crimping. Similarly,the bore seal may be secured to housing 412 using any of a variety ofknown methods including, but not limited to, crimping, welding, oradhesive application. Alternatively, the actuator 418 may be securedwithin housing 412 using an adhesive suitable for providing the desiredseal. Other methods of mounting the actuator 418 in or to housing 412and for providing the desired seal are also contemplated.

In addition, features may be provided for engaging the actuator and/orbore seal with base 420 or a portion of the vehicle or device to whichsystem 497 is mounted, to aid in preventing rotation or other movementof the actuator relative to housing 412 and/or base 420.

In alternative embodiments, actuator 418 may be in the form of apneumatically or hydraulically actuated valve coupled to an end ofhousing 412 so as to enable fluid communication between an outlet of thevalve and bore 424 upon receipt by the valve actuation mechanism of asuitable activation signal. In these embodiments, activation of themechanism to release the tether results in opening of the valve to admita high-pressure fluid into bore 424, resulting in movement of themovable member 415 as described below. Alternatively, actuator 418 maybe positioned remotely from housing 412 but so as to enable fluidcommunication between the actuator and bore 424 upon receipt of asuitable activation signal by the valve actuation mechanism.

A first movable member 415 is configured to slidably move along andwithin bore 424. In the embodiment shown in FIGS. 12-16, member 415 hasa cavity 415 a configured for receiving a portion of actuator 418therein when the valve actuation mechanism is in a pre-activation state.Member 415 also includes a through hole 415 b formed therein forreceiving a locking pin 405 therethrough. Pin 405 forms an interferencefit with edges of hole 415 b or is otherwise secured within hole 415 bso as to ensure motion of the pin 405 in correspondence with movablemember 415.

Movable member is positioned either in fluid communication with actuator418 (described below) or so as to enable fluid communication with theactuator after activation of the valve actuation mechanism. Activationof movable member 415 in the manner described below produces motion ofthe movable member within bore 424.

In one embodiment, a detent feature (not shown) is provided forpreventing movement of the movable member 415 within bore 424 prior toactivation of the valve actuation mechanism. In one particularembodiment, the detent feature is in the form of a knurl, stake, orother deformation (not shown) in a surface of the movable member whichengages a wall of the housing defining the bore 424. In anotherparticular embodiment, the detent feature is formed in the housing,rather than in the movable member 415.

Movable member 415 may be formed from a metallic material or any othersuitable material.

Locking pin 405 extends through movable member opening 415 b and alsothrough housing 412 to project from both of opposed housing slots 12 v.Pin 405 is dimensioned so as to extend from housing 12 a sufficientamount to engage portions of arms 408 and 410 when the valve actuationmechanism is in a pre-activation state, as described below. Pin 405 maybe formed from a metallic material or any other suitable material.

A mounting member 406 is coupled to housing 412 to enable a pair ofactuating arms 408 and 410 to be rotatably mounted thereon. Arms 408 and410, may when taken together be considered as a second movable member408/410. In one embodiment, the mounting member is in the form of a studor shaft portion secured to a side 411 a of base 411 opposite the side411 b along which clamp 499 is mounted. In another embodiment, themounting member is secured directly to the housing 412. However, themounting member may be secured to any other suitable surface.

Arms 408 and 410 are mounted in a stacked fashion on mounting member 406so as to enable free rotation of the arms about the mounting member whenthe arms are not constrained in positions securing tether 422, asdescribed below. If desired, pads or spacers (for example, in the formof washers such as a washer 413) may be positioned along mounting member406 between arm 408 and base 411 and/or between arm 408 and arm 410, tofacilitate smooth, low-friction motion of arm 408 relative to base 411and of arms 408 and 410 relative to each other. The spacers may beformed from any suitable material having a low coefficient of frictionrelative to the material (or materials) from which arms 408 and 410 andbase 411 are formed.

In the embodiment shown in FIGS. 12-16, arm 408 has a notch 408 a formedproximate an end thereof and configured for receiving therein a portionof locking pin 405 when the valve actuation mechanism is in apre-activation state. A through hole 408 e is formed through a body ofthe arm 408 to enable rotatable mounting of the arm on mounting member406. Arm 408 also includes a pair of sloped surfaces 408 b, 408 c whichconverge to define a well 408 d configured for receiving therein alooped portion of a tether 422 when the valve actuation mechanism is ina pre-activation state. The portion of arm 408 including surfaces 408 band 408 c terminates in a rounded end 408 g and defines a “claw” 408 mwhich extends in a first direction across an axis X passing through acenter of mounting hole 408 e.

Arm 410 has a notch 410 a formed proximate an end thereof and configuredfor receiving therein a portion of locking pin 405 when the valveactuation mechanism is in a pre-activation state. A through hole 410 eis formed through a body of the arm 410 to enable rotatable mounting ofthe arm on mounting member 406. Arm 410 also includes a pair of slopedsurfaces 410 b, 410 c which converge to define a well 410 d configuredfor receiving therein a looped portion of a tether 422 when the valveactuation mechanism is in a pre-activation state. The portion of min 410including surfaces 410 b and 410 c terminates in a rounded end 410 g anddefines a “claw” 410 m which extends across axis X passing through acenter of mounting hole 410 e. Claw 410 m extends across axis X in asecond direction substantially opposite the first direction.

As seen in FIG. 13, well 410 d formed by surfaces 410 b and 410 c opensin a direction opposite to that in which the well 408 d opens. Inaddition, claws 408 m and 410 m are configured so as to overlap acrossaxis X when the valve actuation mechanism is in a pre-activation state.In this configuration, the looped portion 422 a of tether 422 is wrappedover the overlapping claws of the arms 408, 410 and extends into wells408 d and 410 d. The overlapping claws thus secure the tether 422 to thevalve actuation mechanism prior to system activation.

Arms 408 and 410 are configured so that claws 408 m and 410 m are in anoverlapping state when the arms are rotated such that notches 408 a and410 a are aligned with each other so as to permit insertion of lockingpin 405 into both notches. Positioning of pin 405 within notches 408 aand 410 a maintains the claws in an overlapping state by preventingrotation of the arms. Arms 408 and 410 may be secured to mounting member406 using a nut or other fastener, or by any other suitable method. Arms408 and 410 may be formed using any suitable method from a metallicmaterial or any other suitable material.

As described above, and when taken together, the arms 408 and 410 andthe associated features when coupled to the housing 412 through mountingmember 406 and the first movable member or element 415 constitute areleasable tether retention mechanism 408/410 that facilitates theretention and subsequent release of an associated tether upon actuationof the system 497.

As shown in FIGS. 12 and 13, prior to activation of the system torelease tether 422, a looped end 422 a of the tether passes through themechanism as shown in FIGS. 12-16, with locking pin 405 residing innotches 408 a and 410 a of arms 408 and 410. In addition, a certainamount of tension force is present in the tether which tends to pull thetether away from the mechanism 497, in the general direction indicatedby arrow “E”.

Referring to FIGS. 14-16, upon receipt of a signal from a crash sensoror other system activation mechanism (not shown), an activation signalis sent to actuator 418. In an embodiment where the actuator is a squib,combustion products from the squib impinge on an end face of firstmovable member 415 in fluid communication with the actuator 418, forcingthe movable member 415 in the direction indicated by arrow “A” in FIG.13. Movement of the first movable member 415 in direction “A” causes thelocking pin 405 to be extracted from notches 408 a and 410 a. Thisreleases the rotational constraints on arms 408 and 410. The tethertension force in direction pulls on the arm ends 408 g and 410 g alongsurfaces 408 c and 410 c, causing them to rotate outwardly aboutmounting member 406, in the directions indicated by arrows “G” and “H”.As rotation of the arms continues and the ends of the arms continue toseparate, the tether looped portion 422 a eventually slides downsurfaces 4108 c and 410 c and over the curved ends of arms 408 and 410,slipping free of the mechanism.

In one embodiment, the tether 422 is operatively coupled to a valve (notshown) controlling a flow of inflation gases from a vent of an airbag(also not shown). The system is structured so that the valve remainsclosed while the tether end 422 a is engaged with mechanism 410.Activation of any of the valve actuation mechanism embodiments describedherein produces rotation of the arms 408 and 410 and release of tetherend 422 a as just described. As tether end 422 a begins to slide off ofarms 408 and 410, tension in the tether starts to relax, permitting thevalve to open and allowing release of inflation gases from the airbag.

Embodiments of the valve actuation mechanism disclosed herein may beactivated to permit release of gases from the airbag in situations wherea smaller or lighter vehicle occupant is present during a crashsituation. Release of a portion of the gases from the inflated airbagprovides a relatively softer, less rigid cushion for the lighter vehicleoccupant.

FIG. 17 shows a particular application of a valve actuation mechanism410 in accordance with the present invention. Referring to FIG. 17, thevalve actuation mechanism may be incorporated into a vehicle occupantprotection system 180 including additional elements such as, forexample, a safety belt assembly 150 and/or an airbag module. FIG. 17shows a schematic diagram of one exemplary embodiment of such aprotection system. valve actuation mechanism 10 may be in operablecommunication with a crash event sensor 210 which is in communicationwith a known crash sensor algorithm that signals actuation of the valveactuation mechanism via activation of actuator 18 based on any desiredcriteria, for example, the occurrence of a collision event, deploymentof a vehicle airbag, the occurrence of a predetermined occupantcondition, or any other desired criteria.

Safety belt assembly 150 includes a safety belt housing 152 and a safetybelt 225 in accordance with the present invention extending from housing152. A safety belt retractor mechanism 154 (for example, a spring-loadedmechanism) may be coupled to an end portion of the belt. In addition, asafety belt pretensioner 156 may be coupled to belt retractor mechanism154 to actuate the retractor mechanism in the event of a collision.Typical seat belt retractor mechanisms which may be used in conjunctionwith the safety belt embodiments of the present invention are describedin U.S. Pat. Nos. 5,743,480, 5,553,803, 5,667,161, 5,451,008, 4,558,832and 4,597,546, incorporated herein by reference. Illustrative examplesof typical pretensioners in system 150 are described in U.S. Pat. Nos.6,505,790 and 6,419,177, incorporated herein by reference.

Safety belt system 150 may be in communication with a crash event sensor158 (for example, an inertia sensor or an accelerometer) including aknown crash sensor algorithm that signals actuation of belt pretensioner156 via, for example, activation of a pyrotechnic igniter (not shown)incorporated into the pretensioner. U.S. Pat. Nos. 6,505,790 and6,419,177, incorporated herein by reference, provide illustrativeexamples of pretensioners actuated in such a manner.

If desired, one or more of sensors 210 and/or 158 may be operativelycoupled to valve actuation mechanism actuator 18 to provide one or moreassociated inputs prompting activation of the valve actuation mechanism,depending on such factors as vehicle occupant weight, elapsed time sincethe occurrence of a collision event, or any other pertinent factors.

It should be understood that the preceding is merely a detaileddescription of various embodiments of this invention and that numerouschanges to the disclosed embodiments can be made in accordance with thedisclosure herein without departing from the spirit or scope of theinvention. The preceding description, therefore, is not meant to limitthe scope of the invention, but should be interpreted to encompass thefull range of literal and equivalent embodiments with regard to theappended claims.

What is claimed is:
 1. A tether release system comprising: a housingcontaining a first end and a second end, and an axial bore; a firstmovable member contained within said housing, and structured to slidablytravel within said axial bore upon actuation of said tether releasesystem; a second movable member structured to operably communicate withsaid first movable member upon actuation of said tether release system,a first portion of the second movable member including a first side, asecond side opposite the first side and facing the first movable member,and an opening structured to permit passage of a portion of a tetherfrom the first side through the opening to the second side prior toactuation of said system; an actuator fixed within said first end ofsaid housing and adapted to operably communicate with said first movablemember upon actuation of said tether release system; and a tetherretainer structured to operably communicate with said second movablemember upon actuation of said system, wherein said second movable memberis configured to release an associated tether upon actuation of saidtether release system.
 2. The tether release system of claim 1 furthercomprising a base attachable to the housing and structured so as toenable attachment of the housing to a vehicle or other device via thebase, and wherein said tether retainer comprises a support elementformed from a portion of the base.
 3. The tether release system of claim1 further comprising a base attachable to the housing and structured soas to enable attachment of the housing to a vehicle or other device viathe base, wherein said second movable member slidably engages said baseupon actuation of said tether release system.
 4. The tether releasesystem of claim 1 further comprising a base attachable to the housingand structured so as to enable attachment of the housing to a vehicle orother device via the base, and wherein the first side of the secondmovable member first portion is structured to be slidable along the baseupon actuation of the tether release system.
 5. The tether releasesystem of claim 1 wherein the second movable member opening has a pairof opposed edges and is sized with respect to the tether retainer suchthat a portion of the tether is supported by at least one edge of thepair of edges along the second side of the first portion of the secondmovable member.
 6. A releasable tether retention system comprising: ahousing; a base attachable to the housing and structured so as to enableattachment of the housing to a vehicle or other device via the base; asupport element operably coupled to the housing and structured forsupporting a tether; and a movable element mounted within the housingand operatively coupled to the support element such that the movableelement is movable from a first position to a second position, whereinthe system is configured to secure the tether to the support elementwhen the movable element is in the first position, and configured suchthat movement of the movable element from the first position to thesecond position forces the tether to disengage from the support element,wherein the support element is formed from a portion of said base, andwherein the movable element includes: a first movable member slidablymounted in the housing, and a second movable member engaged with saidfirst movable member, said second movable member being slidablyengageable with said base upon actuation of said releasable tetherretention system.
 7. A tether release system comprising: a housingcontaining a first end and a second end, and an axial bore; a baseattachable to the housing and structured so as to enable attachment ofthe housing to a vehicle or other device via the base, a first movablemember contained within said housing, and adapted to slidably travelwithin said axial bore upon actuation of said tether release system; asecond movable member adapted to operably communicate with said firstmovable member upon actuation of said tether release system; and asupport element coupled to the housing and structured to engage a tetherto support the tether thereon, wherein said second movable member isstructured to exert a force on the tether when supported on the supportelement, the force being sufficient to remove the tether from engagementwith the support element upon actuation of said tether release system,and wherein the system is structured such that the second movable memberis positioned between the support element and the base prior toactivation of the tether release system to release the tether.
 8. Areleasable tether retention system comprising: a housing; a baseattachable to the housing and structured so as to enable attachment ofthe housing to a vehicle or other device via the base; a support elementoperably coupled to the housing and structured for supporting a tether;and a movable element mounted within the housing and operatively coupledto the support element such that the movable element is movable from afirst position to a second position, wherein the system is configured tosecure the tether to the support element when the movable element is inthe first position, and configured such that movement of the movableelement from the first position to the second position forces the tetherto disengage from the support element, wherein the base includes anopening structured to receive a portion of the tether therethrough forattachment to the support element prior to activation of the releasabletether retention system to release the tether.
 9. The releasable tetherretention system of claim 8 wherein the system is structured such that asecond movable member is positioned between the support element and theopening in the base prior to activation of the tether release system torelease the tether.